In MSDC architectures, leaf switches (also referred to as “top-of-rack” switches (ToRs)) have typically maintained a globally-unique index corresponding to every egress end port. The index was static, being the same for the life of the architecture. When a new flow was established, an ingress leaf switch (ToR) would use the unique index of the egress end port to fetch, among other things, the particular fabric system port used to switch traffic to the egress leaf switch (ToR). However, such a technique scales poorly. Accordingly, it may be impractical to call on an ingress leaf switch (ToR) to maintain globally-unique index information for all end ports so that it may be later used to fetch, among other things, the particular fabric system port needed to reach the egress leaf switch (ToR). There is a need for improved techniques.